Bug 1815 - ReaderWriterLockSlim doesn't behave like MS implement and create deadlock
Summary: ReaderWriterLockSlim doesn't behave like MS implement and create deadlock
Alias: None
Product: Class Libraries
Classification: Mono
Component: System.Core ()
Version: 2.10.x
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Jérémie Laval
Depends on:
Blocks: 1800
  Show dependency tree
Reported: 2011-11-01 19:13 UTC by kyann
Modified: 2011-11-03 20:18 UTC (History)
4 users (show)

Is this bug a regression?: ---
Last known good build:

Test case of the bug (1.33 KB, text/plain)
2011-11-01 19:13 UTC, kyann

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Description kyann 2011-11-01 19:13:10 UTC
Created attachment 802 [details]
Test case of the bug


I've found a deadlock in System.Web.Caching.Cache.
And while looking at the code i've found an deadlock with ReaderWriterLockSlim that doesn't apply with MS implementation.

Take two thread that share a static ReaderWriterLockSlim.

In thread one we do EnterUpgradeableReadLock
then in thread two we do : EnterWriteLock
then in thread one we do : EnterWriteLock

then there is a deadlock, all the thread are locked.

In MS implementation the thread one can enter in WriteLock because it already has the lock.

I joined a test case.
Comment 1 kyann 2011-11-01 19:34:52 UTC
using Mono 2.10.5
Comment 2 Rodrigo Kumpera 2011-11-03 18:10:26 UTC
Jerémie, this one looks pretty serious, can you take a look?
Comment 3 Jérémie Laval 2011-11-03 20:18:58 UTC
Hey, fixed in master and mono-2-10. Thanks for reporting!